The goal of this Phase I proposal is to explore the technical feasibility of minimally invasive ultrasound-guided laser ablation of symptomatic thyroid nodules. Under previous SBIR support, we have developed a cooled laser delivery system for improved laser interstitial thermal therapy (LITT). During this work we obtained FDA 510(k) approval on the laser and applicator system for general soft tissue ablation and coagulation. In our discussions with leading ablation specialists it has been suggested that LITT using our system at the time of thyroid nodule biopsy may have a desirable effect on therapy and clinical management of this disease. In this study we propose to evaluate the technical feasibility of such an approach by first developing a miniature cooled fiber optic applicator which is compatible with current small biopsy needles and optimized for ablation of thyroid nodules. We will then characterize its performance during in vitro and ex vivo tissue experiments. Finally we will perform a pilot clinical study to determine the degree to which the new therapy provides desired clinical results. If Phase I results indicate that such a procedure is indeed technically feasible and beneficial, we will work in Phase II to expand the system capabilities and perform a larger clinical trial aimed at expanding and securing specific indications for the therapy. PUBLIC HEALTH RELEVANCE: If successful, this project could lead to an alternate treatment option for a significant number of thyroid masses which is faster, more controlled, and easier to perform than conventional ethanol injection or surgical therapy. This in turn would translate into easier patient management by resulting in a more effective therapy for symptomatic thyroid nodules requiring fewer follow-ups and repeat therapies. [unreadable] [unreadable] [unreadable]